floor of mouth mucoepidermoid carcinoma (MONDO_0006213, a Monarch Disease Ontology term) is a mucoepidermoid carcinoma of the oral cavity that arises from the floor of the mouth. Also known as: mouth floor mucoepidermoid carcinoma, mucoepidermoid carcinoma of floor of mouth, mucoepidermoid carcinoma of the floor of mouth.